Machine for drilling capstan head screws



Dec. 14, 1948. w,l B BURKE 2,456,245

MACHINE FOR DRILLING CAPSTAN HEAD SCREWS VFiled Jan. 6, 1943 4 Sheets-Sheet' l WILBUR B. BURKE Dec. 14, 1948. w, B, BURKE 2,456,245

v MACHINE FOR DRILLING CAPSTAN HEAD SGREWS Filed Jan. 6, 1943 '4 Sheets-Sheet 3 1Er-9 y wlpBuR BBURKE ATTORNEYS W. B. BURKE MACHINE FOR DRILLING CAPSTAN HEAD scREws Dec. 14, 1948.

Filed Jan. 6, 1943 INVENTOR.v WILBUR B.BURKE v BY v m44., r ATTORNEYS Patented Dec. 14, 1948 MAcmNEfFoRfDmLLING cArsfrANHEAD s'cREWs':

Wmmr uname, nsaclevelana, ohio Application J anuaryi 6, 1943;l Serial No."471,'506

41'Claimsz. (Cl.'.7'7--.26)`1 l The present improvements `relate as`V indicatedto the manufacture of "capstair'lieadscrewsand the like; which are" characterized' by' lhaving: aseries of 'transversethals*"ixrthe' head; -through which a, wire `or` like securing-'means ymaybe passed in order to'holdthcscrewiagainst rotation when in place;rv Suchscrewssordinarilyhave hexagonal headsandv 'the' transverse `holes'would intersect at thefcenter; however',` owing tothe difficulty vof drilling^such holes `clear' throughl ythe head it `has i been the practice to, drill ai central hole. axially in theend oilthe head andthen drill a radial hole in. each'of the sides 'so' as'to intersect such central hole.. Accordinglm;to-complete such capstanheadfseven drilling operations are necessary, which', even-though the parts-"be light, presents a serious manufacturingproblem"when large .numbers arev involved;

The objectl of .the present .invention is nto` pro-1 vde both" an improved' procedure and necessarymechanism for carrying out'the same whereby both such axial. and plural. radial holes mayA be drilled simultaneously, `anditlie manufacture of these capstan. heads .g'1 eatl; ,facilitated"andY the cost correspondingly reduced'.`. Atthe` same time by introducing a new sequence in.: the operations I substantially avoidi the formation. ofanyj burrs in the holeswhichvare highly; objectionable .since if .they project .exteriorlycf the headtlieyjnterfere withthe applicationcf .a wrench,..and it they project interiorlyinto .such .axial holethey, have :to be removed l-or.oi'.l:ler\wisethey,wnuldQinfterfere with the Iriassageacf4 a,.wir.e=-thr,ough ...the

radial holes.:

carrying lout the vfinventilrn',.such disclosed-.means and mode" illustrating, howeverlfbutcne-.cf vari@- ous ways in which .the-principle-offthe invention:

may beused.

In said. annexeddrawings:

Fig. lis afplan. View of.:my:impreaedanachinel as designed for making capstan headserewsf'f.`

Fig.v 2 :.is al central ventiealzsectionatherecf taken on the plane indicatednbyrgthelinef+2 Fig. yl;y

Fig; Seis a lsimilar.".cerxtralf. sectinnzbniifshowin'gf only themeans provided iorareceivingfrand.held.; ing; in: fixed-1 positionlthescrew tofbeedrilled; planer-ofi-the'scctionsbeing indicatedbyfzth'e Tig.A 4 isl a- 'horizontal'sectional view" looking.:4

As illfustratedin Figs. 7 and 8, the capstan head' screw A; whichv is typical of' the `articles which myfiinpr'ovedmachinefis designed to make; hasy a hexagonal head B Inthe end of the latter thereI is drilled an-axia1 hole b, and centrally-efl each' ofthe six faces-thereis drilled a radial hole I b'; which at their inner ends intersect 'such-'axial hole; Th'ese'raelial holes are of prop'errdiameter to receive the wire or f equivalent retainingA means and those which enter'from opposite faces -ofl the head' require to be accurately aligned so i that: such wire may `freelyV pass diametricallythrough thel head. The axial openingl -b4 will desirablyj be of substantially larger diameter'thanthese radial holes; not-only' to facilitate the insertion ofrthe'- securing` wire, but for other-'reasons'which will be explainedY later;

'Referringgtothe illustrative mechanism' shown* in the "drawings, the mainframe of theknachine will be seen tocomprise three vertically spaced'.

plates I; 2y and 3 of generally circular form .whichE are suitably supported one upon the other-,f-'tlre' lowermost 'being-provided with legs 4; str-that themachine: as a whole may l*be raisedto .desired level-above ythe floor lonI which it rests.-

Centrally secured in the upper plate.'I-fi`sa chucking memberv -for receivingv and heidirigs.

the work-piece, e. g. capstanhead screw-,1 While it is being operatedton. 'This member is the formoff a-flangedr bushing that. isaadaptedto bei seated and non-.rotatably held-'man opening;

Blinasuchz; plate. anrl Vthat .is formed'fin' its tupper' facef'with;..a: shallow'recess l' which inlzth'e of adcapstan head` screw, suchvas *.illustrateds'im mensions-to. .closely t the endof theheadwhilie7 leaving the/majcrfportion ofv itsvfside taces'fwexe.v posed.; Thebushingisalso formed withlafcentra'li. opening. ithrouglr whicha drill may enter 'such'i recess-:and- Ithus. .engage the; end fof! thee-head1 as willi 'be presently' described. In 4order lto'-xete'.lfu

the screw in place a handled lever Il) is utilized (see Fig. 3) which is pivotally attached at one end to plate I at a point some distance removed from the bushing 5, such lever being formed in its intermediate portion with an elongated slot I which will pass freely over a nut with its head in recess 'I and yet permit the lever on each side of the slot to engage and press down against the under face of the head, v

Supported in suitable bearings o-n the top of plate I are six radially disposed drill spindles I2 of conventional design, each of which is provided with a drill I3 suitable for drilling one of the radial apertures b in the head b of the screw. These spindles are equidistantly spaced and so related to the work-piece when positioned in the chucking member 5 as to be aligned centrally with one of the faces of such head. These spindles are movable toward and from the workpiece in their respective bearings and are normally held in retracted position by suitable springs I4, but may be advanced simultaneously through the actuating mechanism which will be described later.

Each such spindle I2 is driven through the medium of a spur pinion |5 thereon which meshes with a corresponding pinion I6 on a countershaft or spindle mounted in suitable bearings directly therebeneath on plate 2 of the main frame of the machine, The disposition andwidth of these pinions I5 and I6 is such that they will remain at all times in mesh with each other, irrespective of the reciprocating movement of drill-carrying spindles I2. Spindles I'I are in turn driven by means of bevel pinions I8 on their respective inner ends which mesh with a hollow bevel gear I9 which is rotatably mounted in said plate 2 directly beneath the work holding member or bushing 5 and axially aligned with the recess in said member wherein the work-piece is held. The hub of bevel gear I9 projects downwardly below supporting plate 2 and is provided with a sheave 20 to which driving power is applied by means of a belt 2| from a motor 22 mounted alongside the machine frame. Reciprocably mounted in the bore of bevel gear 9fis a spindle 25 which carries at its upper end a drill 26 designed to drill the central opening b in the end of the head of the screw being operated on; This spindle, just as in the case of the radial drill-carrying spindles I2, is normally retained in retracted position by means of a spring 21 -but may be advanced, i. e. raised vertically, to bring the drill 26 into engagement with the head of a screw clamped in the member 5, as previously described.

From the description thus far given of the machine, it will be seen that upon applying power to sheave 20, rotative movement will be simultaneously imparted to such axially aligned drillcarrying spindle 25 and to the series of radially disposed drill-carrying spindles I2 mounted `on the top plate of the machine frame.

The means provided for advancing radial drillcarrying spindles I2 inwardly into engagement with the work comprise a corresponding series of rocker arms 30 which are piVotally attached at their mid points to plate 2 of the machine frame and which bear at their upper ends respectively on thev outer ends of said spindles, the latter projecting a suitable distance through the adjacent bearing of the spindle, as shown in Fig. 2. Another rocker arm 3| is pivotally attached at an intermediate point to the under side of the lower plate 3 of themachine` frame, theinner end of such arm bearing against the lower end of ghe vertically disposed drill-carrying spindle 5.

For the purpose of actuating these several rocker arms 30 and 3| and thereby advancing the associated drill-carrying spindles, a rotary cam 32 having the form best shown in Figs. 5 and 6 is mounted on the under side of said plate 3. This cam is thus mounted on a tubular bearing`33 which at the same time provides a bearing for the lower end of the vertically disposed drill-carrying spindle 25. Said cam is rotated by means of a worm gear 34 affixed thereto and a worm 35 meshing with such gear and driven through a shaft 36 from an independent source of power, i. e. a source other than the moto-r which drives the several drill-carrying spindles. The cam 32 is provided on its edge with a series of radially projecting cam elements 32a, six in number to correspond with the rockers 3|), which latter are periodically simultaneously actuated by means of pusher bars 31, provided at their inner ends with rollers 38 which ride on the edge of the cam and bearing at their outer ends against the lower ends of said rockers 30.

For the purpose of actuating the rocker arm 3| which in turn serves to reciprocate or advance upwardly the vertical drill-carrying spindle 25, cam 32 is provided on its under face with a series of cam elements 32h disposed to engage a roller 39 on the outer end of said rocker 3|.

As a result of the construction of the aforesaid cam member and of the means whereby it is connected with the several rockers 30 associated with'the radial'drill-carrying spindles I2 and with rocker 3| associated with the vertical drill-carrying spindle 25, it will be seen that such spindles may be all advanced simultaneously to the work-piece with such interval in timing between the movement of the vertical drill-carrying spindle and the plurality of radial spindles as may be desired.

In the operation of the machine the spindles will be continuously driven at such rate of speed as is compatible with securing the best results, having regard to the size of the work-piece, the material of which it is composed and the character of the drills employed. The timing of the advance movements of the drills through the operation of the cam 32, as illustrated in Figs. 9 and 10, vis such that the several radial drills I3 are advanced simultaneously to points which lie within thehole formed in the end of the head wherewith they ultimately intersect. Simultaneously with such advance of drills I3, drill 26 which forms such central hole is advanced, but withdrawal of drills I3 begins before said drill 26 reaches the holes left by the former. As a result, practically no burring action occurs since drill 26 will cut cleanly across the holes left by drills |3 and the latter likewise will leave no burrs when they enter therespective sides of the workpiece. By simultaneously advancing the radial drill spindles, the drills carried thereby will press substantially equally against all sides of the article. There is thus little tendency for the drills to get outr of alignment and strain thereon is minimized.

The machine illustrated and described above, while extremely simple" and designed for hand feeding and removal of the screws' or other workpieces, is nevertheless capable of rapid-and efflcient operation. This is due not merely to the arrangement of drills andactu'ating mechanism therefore whereby the seven holes required in the message;

5. screw head are drilled practically simultaneously;` but also tothe means provided; `for. receiving vand holding the work-piece itself.v It'will be understood that the flanged bushing:'lwhichxconstitutes the principal work-holding or chuckin'gr member is exchangeable for other-similar members having recesses 'I therein of different shapes and sizes to iitwhatever'particular Work-piece is to be operated on. When themachine is inuse*v all that the operator is required todo is to insert and remove successive work-pieces and hold down the handled lever I during the relatively brief period that the drills are in operation. In order to prevent advance movement of the drills before the work is clamped in position in the chucking member, the driving means for the rotary cam 32 may be made subject by familiar means to the control of the operator or such rotation can be timed to thus advance the drills at suitable intervals which will allow sucient time for placing and removing the successive work-pieces.

It Will be understood that, if desired, in order to more accurately guide the radial drills I3 to the work, a suitable jig (not shown) may be employed.

Also, as shown in Fig. 11, other means than the hand-operated lever Ill, may be utilized to retain the work in place. In the modified construction of the figure in question the handled lever I0 is replaced by a lever 40 pivotally attached at approximately its mid-point to the top plate I. The inner end of said lever is provided with a slot 4I which, when such end is depressed, is adapted to engage the bolt head inthe same manner as slot I I in lever IU. Said lever is actuated by means of a treadle 42, suitably mounted in the lower portion of the machine frame and connected with the outer end of the lever through the medium of a link 43, a bell-crank 44 and a beveled slide 45 that rests on the top of plate I in line with such lever end. The latter is provided with downwardly directed bevel face opposed to the bevel face of the slide; accordingly when the latter is urged inwardly by actuation of the foot lever 42, the slotted end 4I of lever 40 will be pressed forcibly down on the head of a bolt seated in the chucking member 5.

The foregoing arrangement obviously has the advantage of having both hands of the operator free, so that he can simultaneously feed and remove nuts, thus further expediting the operation of the machine.

Other modes of applying the principle of my invention may be employed instead of the one explained, change being made as regards the means and the steps herein disclosed, provided those stated by any of the following claims or their equivalent be employed.

, I therefore particularly point out and distinctly claim as my invention:

l, In a machine of the character described having means adapted to receive and hold in xed position an article such as a capstan head screw blank with sides and end accessible for operation and a drill-carrying spindle aligned with the axis of the article thus held and movable towards and from such end of the latter and a plurality of similar spindles radially disposed in a plane transverse of such axis and movable to-ward and from such sides of the article having means adapted to advance and retract said aligned spindle and means adapted to advance and retract said plural spindles, said advancing and retracting means being timed to clear the center of said article of said plural spindles prior to completion of the advance movement .oisaid aligned; spindle, driving means for saidy .spindles ,comprising ,a l hollow bevel gear rotatable aboutl said.axially aligned. spindle, radially disposed spindles corresponding with said pluralspindles andA having bevel pinions meshingY with said bevel gear-:,and spur pinions;i

interconnecting each pair. of. corresponding spindles.. y

2. Inamachine of the characterdescribed, the combination of means adapted. to-,receivegand hold in fixed position an article such as a capstan head screw blank with sides and end accessible for operation, a drill-carrying spindle below and aligned with the axis of the article thus held and movable towards and from such end of the latter, a plurality of similar spindles radially disposed in a plane transverse of such axis and movable toward'and from such sides of the article, springs normally retracting said spindles, respectively, rocker arms adapted to advance said spindles, respectively, and a cam at the lower end of and rotatable about said axially aligned spindle and having an end face for actuating the rocker for said spindle and a series of edge faces for actuating the rockers for said plural spindles.

3. In a machine of the character described having means adapted to receive and hold in xed position an article such as a capstan head screw blank with sides and end accessible for operation and a drill-carrying spindle aligned with the axis of the article thus held and movable towards and from such end of the latter and a plurality of similar spindles radially disposed in a plane transverse of such axis and movable toward and from such sides of the article, springs normally retracting said spindles, respectively, rocker arms adapted to advance said spindles, respectively, a rotatable cam below said radially disposed spindles having elements for actuating said rockers, respectively, and driving means for said spindles comprising a hollow bevel gear rotatable about said axially aligned spindle, radially disposed spindles corresponding with said plural spindles and having bevel pinions meshing with said bevel gear, and spur pinions interconnecting each pair of corresponding spindles.

4. In a machine of the character described having means adapted to receive and hold in xed position an article such as a capstan head screw blank with sides and end accessible for operation and a drill-carrying spindle aligned with the axis of the article thus held and movable towards and from such end of the latter and a plurality of similar spindles radially disposed in a plane transverse of such axis and movable toward and from such sides of the article, springs normally retracting said spindles, respectively, rocker arms adapted to advance said spindles, respectively, a cam below said radially disposed spindles rotatable about said axially aligned spindle and having an end face for actuating the rocker for said spindle and a series of edge faces for actuating the rockers on said plural spindles, and driving means for said spindles comprising a hollow bevel gear rotatable about said axially aligned spindle, radially disposed spindles corresponding with said plural spindles and having bevel pinions meshing with said bevel gear, and spur pinions interconnecting each pair of corv responding spindles.

WILBUR B. BURKE.

7 REFERENCES 'CITED The following references are of record in the 111e of this patent:

UNITED STATES PATENTS Number Name Date Tejada Nov. 16, 1897 Everson July 8, 1902 Trundle June 10, 1919 McKee Dec. 14, 1926 10 Number Number Germany Apr. 9, 1930 

